For example, as disclosed in Patent Literature 1, the axial gap motor is a motor in which a rotor is arranged to be opposed to the lateral surface in one direction or each of the lateral surfaces in both directions of a stator with a predetermined gap. Compared with a radial gap motor, it is possible to reduce the overall length in a rotating shaft direction irrespective of the magnitude of an output.
The stator is formed by plural core members annularly coupled to one another centering on the axis line direction of a rotor output shaft. Consequently, it is possible to easily assemble the stator simply by applying a winding wire to the core members in advance and coupling and connecting the core members.
However, for example, as disclosed in Patent Literature 2, in the case of a so-called single rotor axial gap motor in which one rotor is arranged on one surface of a stator, it is desirable to provide, on a counter rotor side of a stator core, a yoke section configured by coupling yoke strips provided in core members, realize an expansion of a magnetic flux path, and obtain a higher output.
However, in the case of the divided core-type axial gap motor explained above, since the end faces of the yoke strips of the core members adjacent to each other are set in contact with each other to form one magnetic circuit, it is likely that a contact area cannot be secured sufficiently large and magnetic resistance increases. If the contact area cannot be secured large, for example, since the end faces in contact with each other tend to be separated when receiving a shock, it is likely that the magnetic resistance further increases and magnetic loss of the motor increases.
As an example of a use of the axial gap motor, for example, there is a pump device disclosed in Patent Literature 3. The pump device includes a motor chamber and a pump chamber divided via a predetermined partition wall. The stator is arranged in the motor chamber and the rotor is arranged in the pump chamber. An impeller for a pump is integrally provided in the rotor to make it possible to discharge, with the torque of the rotor, fluid taken into the pump chamber.
However, when the divided core-type axial gap motor is used in the pump device, there is a problem explained below. In the axial gap motor disclosed in Patent Literature 1, coupling means for coupling the core members, a bridge for processing a connecting wire, and the like are provided on the lateral surface of a flange section of an insulator.
Therefore, since a part of the flange section further projects than a teeth surface, when the axial gap motor is incorporated in the motor chamber of the pump device, a gap between a teeth surface of the stator and a magnet surface of the rotor inevitably increases. As a result, a motor output decreases.